Fig. 2: Depletion of Eif2s2 in oocytes impairs oocyte maturation.

A Representative image of oocytes ovulated and corpus luteum 13 h and 48 h after human chorionic gonadotropin (hCG) treatment. B The number of ovulatory oocytes per female mouse and corpora lutea in each ovary, n = 3 females each genotype. C Immunofluorescence staining of α-tubulin showing spindle assembly in oocytes ovulated by WT and Eif2s2-ZcKO mice. D The percentage of first polar body (PB1) extruded (WT: n = 165, Eif2s2-ZcKO: n = 105) and abnormal spindle assembly in superovulated oocytes of WT and Eif2s2-ZcKO mice. E–G Representative images and the percentage of germinal vesicle breakdown (GVBD), PB1 extrusion and abnormal spindle assembly in WT and Eif2s2-ZcKO oocytes cultured in vitro. n = 3, and 61-94 oocytes were analyzed in each repetition. H DAPI staining of the oocytes with non-surrounded nucleolus (NSN) and surrounded nucleolus (SN) chromatin configurations in WT and Eif2s2-ZcKO oocytes. I The percentage of NSN and SN type oocytes isolated from WT (n = 244 oocytes) and Eif2s2-ZcKO (n = 168 oocytes) mice. J Immunofluorescence staining of H3K4me3 and H3K27me3 in WT and Eif2s2-ZcKO oocytes. K Quantification of H3K4me3 fluorescence intensity (n = 30 oocytes). In each experiment, n ≥ 3 biological replicates. Bars indicate the mean ± SD. A two-sided Student’s t-test was used to determine P values. (*P < 0.05, **P < 0.01, and ***P < 0.001). Scale bar: 100 μm (A) and 25 μm (C, E, G, H, J).